Enhanced rack/cabinet mobility and stability for a server rack

ABSTRACT

A mobility apparatus. The mobility apparatus may include a continuous fixed-length rail attached horizontally to a bottom structural member of the front or the rear of a server rack. The continuous fixed-length rail exceeds a width of the server rack by an equal amount on either side of the server rack. The mobility apparatus also includes a lower rail portion attached to a lower edge of the continuous fixed-length rail; a raised rail portion attached to an extended length of each portion of the continuous fixed-length rail; and at least one wheel attached to an underside of each end of the extended length of the continuous fixed-length rail.

BACKGROUND

The present invention generally relates to rack-mounted electronicsystems and equipment racks, and more particularly to enhanced cabinet(i.e., rack) mobility and stability for a server rack.

A potential tipping hazard exists when moving a server rack within acustomer datacenter. The tipping hazard is particularly acute during theinstallation of the rack, which includes maneuvering the rack intoposition and aligning the rack with the other racks.

SUMMARY

According to one embodiment of the present invention, a mobilityapparatus is provided. The mobility apparatus may include a continuousfixed-length rail attached horizontally to a bottom structural member ofa front or a rear of a server rack. The continuous fixed-length railexceeds a width of the server rack by an equal amount on either side ofthe server rack. The mobility apparatus also includes a lower railportion attached to a lower edge of the continuous fixed-length rail; araised rail portion attached to an extended length of each portion ofthe continuous fixed-length rail; and at least one wheel attached to anunderside of each end of the extended length of the continuousfixed-length rail.

According to another embodiment of the present invention, a mobilityapparatus is provided. The mobility apparatus includes a left-hand railportion and a right-hand rail portion each attached horizontally to abottom structural member of a front or a rear of a server rack; a lowerrail portion permanently attached to a lower edge of each of theleft-hand rail portion and the right-hand rail portion; a raised railportion permanently attached to an extended length of the left-hand railportion and the extended length of the right-hand rail portion; and atleast one wheel attached to the extended length of each of the left-handrail portion and the right-hand rail.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example and notintended to limit the invention solely thereto, will best be appreciatedin conjunction with the accompanying drawings, in which:

FIG. 1 is an isometric view of a rack, according to an embodiment;

FIG. 2 is an alternate view of a rack, tilted at 12.5° from horizontal;

FIG. 3 is a front view of a rack;

FIG. 4 is an isometric view of a rack with mobility structure attached,according to an embodiment;

FIG. 5 is an alternate isometric view of one side of the mobilitystructure, according to an embodiment;

FIG. 6 is an alternate isometric view of the mobility structure,according to an embodiment; and

FIG. 7 is a top view of a rack inserted between two installed racks,according to an embodiment.

The drawings are not necessarily to scale. The drawings are merelyschematic representations, not intended to portray specific parametersof the invention. The drawings are intended to depict only typicalembodiments of the invention. In the drawings, like numbering representslike elements.

DETAILED DESCRIPTION

Detailed embodiments of the claimed structures and methods are disclosedherein; however, it can be understood that the disclosed embodiments aremerely illustrative of the claimed structures and methods that may beembodied in various forms. This invention may, however, be embodied inmany different forms and should not be construed as limited to theexemplary embodiments set forth herein. In the description, details ofwell-known features and techniques may be omitted to avoid unnecessarilyobscuring the presented embodiments.

References in the specification to “one embodiment”, “an embodiment”,“an example embodiment”, etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

For purposes of the description hereinafter, the terms “upper”, “lower”,“right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, andderivatives thereof shall relate to the disclosed structures andmethods, as oriented in the drawing figures. The terms “overlying”,“atop”, “on top”, “positioned on” or “positioned atop” mean that a firstelement, such as a first structure, is present on a second element, suchas a second structure, wherein intervening elements, such as aninterface structure may be present between the first element and thesecond element. The term “direct contact” means that a first element,such as a first structure, and a second element, such as a secondstructure, are connected without any intermediary conducting, insulatingor semiconductor layers at the interface of the two elements.

In the interest of not obscuring the presentation of embodiments of thepresent invention, in the following detailed description, someprocessing steps or operations that are known in the art may have beencombined together for presentation and for illustration purposes and insome instances may have not been described in detail. In otherinstances, some processing steps or operations that are known in the artmay not be described at all. It should be understood that the followingdescription is rather focused on the distinctive features or elements ofvarious embodiments of the present invention.

The present invention generally relates to enhanced cabinet (i.e., rack)mobility and stability for a server rack. An enterprise's product safetyengineers may test a populated rack configuration to ensure compliancewith government and industry safety standards. For example, rack designthat produces a static tilt of up to approximately 12.5° (shown in FIG.2) may be an acceptably safe design in a dynamic environment, such aswhen moving the populated rack on its casters. FIG. 2 shows the statictilt formed by a side edge of the rack and the horizontal surface (i.e.,the floor). The static tilt may also be formed by a front or back edgeof the rack and the horizontal surface.

Generally, meeting product safety tip/tilt requirements for electronicrack designs involves additional safety measures. The ElectronicIndustries Alliance (EIA) is an industry standards organization thatpromotes, among other measurements, standard interior and exterior rackdimensions. The height of an EIA-compliant rack is measured in standardrack units of approximately 44.45 mm (1.75 in) each. The typicalfull-size rack is 42 rack units (U) high.

Standardizing measurements implies that equipment can be interchangeablyinstalled in racks of any manufacturer, and is not limited to beinginstalled in only racks from the equipment manufacturer. Standardizationfacilitates datacenter management, since floor space for future rackscan be reliably planned. Additionally, equipment and racks can bereplaced without impacting other racks that are currently installed.

To prepare a rack that is fully populated with equipment for shipment,as much as half of the equipment is depopulated from the the upperlocations of the rack, for example locations above approximately 32 U,to lower the overall center of mass and make the rack more stable. Thedepopulated equipment is shipped separately and re-installed at thecustomer datacenter. It should be noted that prior to shipment, as partof the final integration and test, the rack is installed and configuredwith the equipment and options ordered by the customer. It would beadvantageous to ship the tested rack at this point. However, the extrasteps of partially depopulating, shipping the equipment separately andre-installing the depopulated equipment at the customer data center areperformed. This results in additional labor and shipping costs to thecustomer.

Optionally, ballast weight is added to the bottom of the rack to lowerthe overall center of mass. Preferably, the ballast weight, such aswelded-in steel ballast, is fixed to the rack to prevent shifting. Thecustomer may incur costs to re-evaluate the structural capacity of thedata center raised floor to ensure the rack, plus additional ballastweight, can be safely installed. The customer may also incur costs forthe additional ballast weight and the increased shipping costs becauseof the added weight.

Similarly, outrigger extensions, in varying configurations, may beattached parallel to each rack side (FIG. 1) to widen the wheel base.Typically, the tipping hazard is more acute from side to side becausethe rack is narrow relative to its height. As currently practiced, theside-attached outrigger extensions cannot remain attached when slidingthe rack into a location between two installed racks, as in FIG. 7,because the attached outrigger extensions increase the rack width to ameasurement greater than that of the install location. Therefore, theattached outrigger extensions are removed before sliding the rack intothe final installed position. This raises a product safety exposure,since the rack becomes unstable during the outrigger extension removal,and while sliding the rack into final position.

Ideally, it may be desirable to attach extension wheels parallel to therack, to provide stability, yet to safely allow placing the rack intoits final installed position prior to removing the extension wheels. Thewheels may be attached to either the front of the rack, or to the rearof the rack. Embodiments of the present invention are described withreference to attaching the wheels to the front of the frame. However inan embodiment, the wheels may be attached to the rear of the frameinstead. The embodiments of attachable extension wheels are described indetail below referring to the accompanying drawings FIGS. 1-6.

FIG. 1 illustrates a typical rack (not to scale) into which computingequipment, including power supplies, network switches, computer servers,and storage devices, may be installed. The following embodiments areillustrated using an exemplary standard 42 U rack, having an overallexternal rack width of approximately 644 mm (25.4 in.), an overallexternal rack depth of approximately 1098 mm (43.3 in.), and an overallheight of approximately 2015 mm (79.3 in.). However, the variousembodiments are not so limited, and may be applied to racks of otherdimensions. As FIG. 1 illustrates, the rack occupies a generallyrectangular footprint on the data center floor. The side to side tippinghazard exists because the rack width is less than the rack depth, andthe rack width is narrow relative to the rack height.

Referring now to FIGS. 3-4, a front view (FIG. 3) and an isometric view(FIG. 4) of a server rack 10 with structure 100 installed areillustrated, according to an embodiment.

FIG. 3 illustrates the server rack 10, having an installed front door11, bottom structural member 12 and side structural members 13.

FIG. 4 is an isometric view of a server rack 10 with structure 100installed, according to an exemplary embodiment. Structure 100 is anextension system that may be attached to either the front or rear of arack to provide stability for a server rack, particularly duringinstallation. Structure 100 may be made of any material known in theart, such as steel. In the illustrated embodiment, structure 100includes a continuous fixed-length rail 33, two raised portions of rail36, a lower rail portion 34, two wheels 30, six total attachment points31, and two strengtheners 35.

The continuous fixed-length rail 33 is attached to the bottom structuralmember 12, parallel to the front of the server rack 10 and parallel tothe floor. To more clearly illustrate the structure 100, the server rack10 is shown without the front door. However, the structure 100, may notprevent an attached front door from opening. As shown in FIG. 3, thefront door 11 of the server rack 10 does not extend beyond, i.e., cover,the bottom structural member 12 of the server rack 10, thus permittingattachment of the structure 100 without impairing the operation of thefront door 11.

The continuous fixed-length rail 33 of the structure 100 is attached tothe bottom structural member 12 of the server rack 10 at attachmentpoints 31. For structural strength, three attachment points 31 areconfigured in a triangular pattern along the side structural member 13and the bottom structural member 12 of the server rack 10. The structure100 is attached to the server rack 10 as part of the preparation forshipping, and typically remains attached until the server rack 10arrives at the datacenter and is rolled into its final position.Therefore, the continuous fixed-length rail 33 may be attachedtemporarily to the bottom structural member 12 by appropriate removablefasteners, such as bolts and screws. The attachment point holes may comein different shapes and sizes, such as, for example, bolt holes,threaded holes for #12-24 or #10-32 screws, tapped holes, or squareholes. The number, size, and placement of the attachment points 31 maybe configured according to the design of the particular server rack 10,and thus may differ from the embodiment shown in FIG. 4. However, theexemplary embodiment of FIG. 4, permits mobility and installation of theserver rack 10, unimpaired operation of the front door 11, and removalof the structure 100 once the server rack 10 is installed, as forexample, between two existing racks.

It should be understood that the rear of the server rack 10 hasstructural members corresponding to those of the front of the serverrack 10, including a rear door, rear bottom structural member, andattachment points. The structural members of the rear of the server rackperform substantially similar functions as those on the front of theserver rack 10. Consequently, FIG. 4 may show either the front or therear of a server rack.

The length of the continuous fixed-length rail 33 may be determined interms of the height, width, and depth proportions of the server rack 10.For the standard 42 U frame of the present embodiment, the length of thecontinuous fixed-length rail 33 is approximately 1.0 m (39.37 in.).

The extended length 32 and the rack side form two sides of a triangle,with the apex being the rear wheel of the server rack 10. In the FIG. 4embodiment, each extended length 32 is approximately 0.5 m (19.6 in.).The length of the extended length 32 depends, in part, on the height,depth and width of the rack. For example, the length of the extendedlength 32 may be increased to compensate for a longer rack depth becausethe rack depth affects the overall rack stability by changing thedimensions of the formed triangle. Consequently, adjusting the extendedlength 32 permits customizing the structure 100 to server racks ofdifferent dimensions, while preserving safety standards.

Other considerations that affect the length of the extended length 32include well-known standard measurements used in datacenter managementand planning. These specify, among other things, the distance betweenrows of installed server racks, and the width of door openings in thedatacenter and in the freight elevators, all of which affect rackplacement and maneuverability. The measurements and available floorspace in the shipping vehicle, such as a truck or cargo container, alsoinfluence the length of the extended length 32. For example, the serverrack 10 and the attached structure 100 may be fixed to a pallet andloaded on the shipping vehicle. The overall length of the structure 100affects the width of the pallet, which, in turn, affects the number ofpallets that the shipping vehicle can hold. Therefore, efficient andeconomical use of shipping space may influence the length of theextended length 32.

Two raised portions of rail 36 are permanently attached, for examplewelded, to and are substantially perpendicular to, the extended portionsof the continuous fixed-length rail 33. Therefore, the strengthener 35is substantially a right triangle which is permanently attached, forexample welded, to the raised rail portion 36 and the extended portionof the continuous fixed-length rail 33. The placement of thestrengthener 35 as shown, may improve transfer of the weight of theserver rack 10 to the wheel 30. The strengthener 35 may also addstability and strength to the weld that permanently joins the raisedportion of rail 36 to the continuous fixed-length rail 33 along theextended length 32. However, the strengthener 35 may be locatedelsewhere along the raised rail portion 36. Additionally, thestrengthener 35 may be eliminated, for example, if the structure 100 ismanufactured from a sufficiently heavy gauge material.

The lower rail portion 34 is permanently attached, for example welded,to and is substantially perpendicular to, the lower edge of thecontinuous fixed-length rail 33. The raised rail portion 36 and thelower rail portion 34 are not a continuous rail or surface. The lowerrail portion 34 is positioned such that the attachment points 31 areexposed. Consequently, the server rack 10 may be installed betweenexisting racks and the structure 100 may be detached by unfastening thetemporary removable fasteners at the attachment points 31. Inimplementations where access to the interior of the server rack 10 isneeded to remove the temporary fasteners at the attachment points 31,such as bolts and nuts, the front door 11 may be opened or removed, asnecessary.

The standard server rack 10 is typically equipped with an internal wheelat each of its corners. The internal wheels substantially support theserver rack 10 during moving, and aid in levelling the server rack 10during installation. The wheels 30 of the structure 100 provideadditional stability and support by contacting the floor if the serverrack 10 begins to tip, thus preventing the server rack 10 from exceedingthe maximum 12.5° angle from horizontal. Having the wheel 30approximately 6.35 mm (0.25 in.) to approximately 2 mm (0.125 in.) fromthe floor provides both the required stability and the ease of movementover a variety of floor surfaces.

The wheel 30 is permanently attached to the underside of the raised railportion 36. The wheel 30 may include any type of caster, wheel, orattached device that enables movement of the server rack 10, includingswivel, fixed, adjustable height, casters and equipped with brakefeatures, skid shoes and glides. The height of the raised rail portion36 may be determined based on the height and type of wheel 30. Forexample, a wheel 30 having a larger or smaller diameter may increase ordecrease, respectively, the height of the raised rail portion 36 fromthe floor. A wheel 30 may be selected that continuously contacts thefloor while the structure 100 is attached to the server rack 10.However, a wheel 30 having a diameter such that the bottom of the wheeldoes not contact the floor facilitates moving the server rack 10 overfloors of varying heights, such as level concrete, carpet, and raisedfloor tiles which tend to be uneven.

FIGS. 5-6 illustrate a structure 200 which is an alternate embodiment ofthe structure 100 that is illustrated with reference to FIG. 4. Commoncomponents in FIGS. 5-6 having corresponding reference numerals to thoseillustrated in FIG. 4 perform the same functions as describedpreviously.

FIG. 5 illustrates a left-hand portion of the structure 200. Theleft-hand portion and a corresponding right-hand portion (not shown)together comprise an alternate embodiment of the structure 100.

FIG. 6 illustrates those portions of the structure 100 that may beremoved to form the alternate embodiment of structure 200 of FIG. 5. Thediagonally-striped portion of the continuous fixed-length rail 33 may beremoved, along with the cross-hatched section of the lower rail portion34 to form two separate portions (left-hand and right-hand) of thestructure 100. In an alternative embodiment, the diagonally-stripedportion of the continuous fixed-length rail 33 may be removed, leavingthe cross-hatched section of the lower rail portion 34 attached. Inanother alternative embodiment, the cross-hatched section of the lowerrail portion 34 may be removed, leaving the diagonally-striped portionof the continuous fixed-length rail 33 attached.

FIG. 7 illustrates a method for installing a server rack 10 having thestructure 100 attached. At step 20, the structure 100 is installed onRack 2 prior to installing Rack 2. Rack 1 and Rack 3 are two in a lineof server racks that are previously installed, for example, on thedatacenter floor. At step 21, Rack 2 is rolled into position betweenRack 1 and Rack 3. The front of Rack 2 may be installed substantiallyflush with those of Rack 1 and Rack 3, without first removing thestructure 100, whether the structure 100 is attached to the front or therear of the rack 10. At step 22, having been finally positioned betweenRack 1 and Rack 3, the structure 100 is detached from the Rack 2. Thestructure 100 may be attached to either the front or the rear of theserver rack 10.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the invention.The terminology used herein was chosen to best explain the principles ofthe embodiment, the practical application or technical improvement overtechnologies found in the marketplace, or to enable others of ordinaryskill in the art to understand the embodiments disclosed herein.

What is claimed is:
 1. A mobility apparatus comprising: a left-hand railportion and a right-hand rail portion each attached horizontally to abottom structural member of a front of a server rack, wherein theapparatus is temporarily attached, by one or more removable fasteners,to the front of the server rack by at least one set of attachment pointshaving at least three holes per attachment point; a lower rail portionpermanently attached to a lower edge of each of the left-hand railportion and the right-hand rail portion; a raised rail portionpermanently attached to an extended length of the left-hand rail portionand an extended length of the right-hand rail portion, wherein eachextended length extends laterally beyond the front of the server rack;and at least one wheel attached to the extended length of each of theleft-hand rail portion and the right-hand rail portion, wherein the atleast one wheel is selected from a group consisting of: 1) a casterequipped with brake; 2) a swivel caster; 3) a fixed caster; 4) anadjustable height caster; 5) a skid shoe; and 6) a glide.